Concept:A balance of payments deficit occurs when a country's imports and outflows are greater than its exports and inflows.
Corrective measures aim at reducing imports or increasing exports.
Explanation:Import substitution means producing goods locally instead of importing them.
This reduces foreign exchange spending and helps correct the deficit.
Currency depreciation makes imports more expensive, so it does not encourage imports; option B is incorrect.
Currency appreciation makes imports cheaper and encourages them, which worsens the deficit; option A is incorrect.
Restricting trade with all countries is extreme and harms the economy; option D is not suitable.
Therefore, adopting an import substitution strategy is the appropriate policy measure.
Answer:C. Adopt import substitution strategy